1. Field of the Invention
The present invention relates to a video cassette tape recorder (hereinafter referred to as "VCR") and, more particularly, to a head cleaner for such a VCR and automatic head cleaning apparatus and method.
2. Description of the Prior Art
When foreign substances become attached to VCR heads, the ability of the heads to accurately scan video signals from cassette tapes is reduced. That is, the heads become relatively insensitive to tape. However, conventional VCRs have no provision for automatically removing such foreign substances upon the occurence of such insensitivity. Therefore, the user has to discover or at least recognize the insensitivity of VCR heads. After having discovered that the sensitivity of the head is no longer acceptable, the user must remove the cover from the VCR body and manually clean parts including the heads to remove foreign substances attached to the heads. Alternatively, a head cleaning tape may be used for removing the foreign substances.
It is difficult for VCR users without expert knowledge to discover with accuracy the insensitivity of the VCR heads by merely viewing the screen images produced by the VCR. Furthermore, the VCR may become damaged during the manual removal of foreign substances from the heads by the normal VCR user.
To avoid the above problem and inconvenience to the user of having to recognize the insensitivity of VCR heads and to clean the heads manually, or use a head cleaning tape, an apparatus has been provided for automatically recognizing the VCR head insensitivity and for automatically removing the foreign substances from the heads.
FIGS. 1A and 1B illustrate an example of a conventional head cleaning device that has been proposed to meet the above-mentioned requirement. As shown in these figures, a head cleaning device comprises an operating shaft 3 disposed to one side of a VCR drum head 1 supporting a head, and adapted to be reciprocated laterally by a solenoid 2. A connecting member 5 is pivotally connected at one end to the operating shaft 3 and mounted for pivotal motion on a fixed shaft 4 in response to reciprocating movement of the operating shaft 3. A support member 6 is pivotally connected to the other end of the connecting member 5 and adapted to support a cleaning member 7. Upon pivotal movement of the connecting member 5, the support member 6 is moved to bring the cleaning member 7 into contact with the rotating drum head 1 and clean the head.
When a foreign substance attached to the head is sensed by the user of the VCR during the playback operation, power is supplied to the solenoid 2 so that the operating shaft 3 moves in the direction indicated by an arrow "a" in FIG. 1B. As a result, the connecting member 5 pivots about the fixed shaft 4 in the direction indicated by an arrow "b" in FIG. 1B, thereby causing the cleaning member 7 attached to the support member 6 to be in close contact with the drum head 1. At this time, the drum head 1 is in a rotating state as by operating the VCR in the playback mode. Accordingly, the head can be cleaned through contact by the cleaning member 7.
However, the conventional head cleaning device shown in FIGS. 1A and 1B has the following problems.
First, the head cleaning device is inevitably mounted above the area for loading a cassette tape due to its manner of operation. As a result, the head cleaning operation cannot be carried out during the loading of the cassette tape. Furthermore, the head cleaning device occupies a large space to adversely affect the compactness of the VCR.
Second, the retraction force of the solenoid is directly transmitted through the operating shaft.
Third, when contacted by the cleaning member, the head may become worn and damaged due to the retraction force.